The continuing evolution of integrated circuit technology has witnessed refinements in integrated density, performance and robustness against severe (e.g. radiation) environments. In the course of this development the microelectronics industry has achieved semiconductor wafer implementations of increased (functional) complexity circuits, intended to operate at enhanced signal processing speeds, known as very high speed integrated circuits. Because of the number of critical performance requirements that have been placed on these designs (e.g. survivability in severe operating environments, signal processing power, increased system complexity, and wafer mapping capability), the processing methodology of very high speed integrated circuits has had placed upon it a large number of demands not heretofore encountered in semiconductor fabrication technology.